{"product_id":"watch-craft-mainspring-3011w-for-gruen-300-301-307-327-328-329-350-etc-alloy","title":"WATCH-CRAFT Mainspring 3011W for Gruen 300, 301, 307, 327, 328, 329, 350, etc. - Alloy","description":"\u003cp\u003e\u003cstrong\u003eWATCH-CRAFT \u003c\/strong\u003eMainspring 3011W for \u003cstrong\u003eGruen\u003c\/strong\u003e 103, 300, 301, 307, 327, 328, 329, 350, 520, 530, 531 caliber movements plus perhaps others, white alloy, new in envelope. See images for precise mainspring specifications. I likely have several of these so the one you get may differ slightly from the images.  I specialize is hard to find watch parts so I usually have whatever you might need and all watch parts are unconditionally guaranteed. Images do a pretty good job of representing the item.\u003c\/p\u003e","brand":"C \u0026 E Marshall","offers":[{"title":"Default Title","offer_id":48896397902132,"sku":"PMS-CEM3011WA-09","price":8.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0849\/3341\/1124\/files\/2025-09-1712.39.00.jpg?v=1758138143","url":"https:\/\/www.vintagetimeparts.com\/products\/watch-craft-mainspring-3011w-for-gruen-300-301-307-327-328-329-350-etc-alloy","provider":"Vintage Time Parts","version":"1.0","type":"link"}